Phish's fourth studio album is a loose concept album about a person in the midst of relationship problems trying to sleep and getting haunted by dreams. For a recording by a band that is not particularly revered for their studio output, it is surprisingly focused and accessible making it easily their best studio album.
The artwork (created by David Welker) depicts the sleeper in the midst of his fitful slumber. Not only is it a beautifully crafted picture, but when seen in it's entirety (the front cover and back cover together), every song on the album (save one) is represented.
Some of them are more immediately obvious (it's hard to miss the maze under the bed for "Maze" or the fact that the sleeper is laying diagonal in his bed like in the song "Lengthwise") and some less so (the ice skater to represent the song "It's Ice" is seen in the reflection of the mirror off to the right) but each and every song, with the exception of "The Horse", is accounted for in one manner or another. The band would correct the omission of "The Horse" on the cover of their next album, Hoist.